Gas scrubber, entrainment separator and combination thereof

ABSTRACT

A gas scrubber for removing particles carried in suspension by gas is used with or without a specific entrainment separator. The scrubber has (1) a gas-conducting conduit with a portion having an inner surface that diverges in the direction of gas flow, (2) a diverter that is disposed in this portion of the conduit and that has an opposed diverging surface with a greater degree of divergence, and (3) a pipe that feeds scrubbing liquid to that surface of the diverter for flowing liquid into the downward flow of gas. Preferably, the diverter is supported from above and is resiliently urged upwardly so that the diverter is automatically moved by a change in the rate of gas flow. The scrubber provides an annular flow of gas that is changed to a helical downward flow by the specific entrainment separator, disposed below the diverter and having helically extending elongated plates in a vertical conduit within a chamber. A frustoconical diverter is disposed below the bottom open end of that vertical conduit to change the direction of the gas leaving the vertical conduit. The elongated plates are radially disposed within the vertical conduit and extend in a helical manner about the longitudinal axis of that conduit. Another conduit communicates tangentially with a sidewall opening of the chamber adjacent its top to exhaust the gas from the annulus between the chamber and the vertical conduit. Accumulated liquid is removed from the bottom of the chamber.

United States Patent Heeney Mar. 26, 1974 GAS SCRUBBER, ENTRAINMENTSEPARATOR AND COMBINATION THEREOF [62] Division of Ser. No. 748,846,July 30, 1968, Pat. No.

[51] Int. Cl Bold 45/12 [58] Field of Search 55/235, 236, 237, 238,55/426, 427, 456, 457

[ 56] References Cited UNITED STATES PATENTS 1,836,004 12/1931 Becker55/456 1,952,308 3/1934 Bowen 55/236 2,624,503 1/1953 Kutcher... 55/2381,548,066 8/1925 Steinbart 55/456 3,420,040 l/l969 Neely et al... 55/4562,208,673 7/1940 Hopkins 55/456 3,358,413 12/1967 Kalika 55/238 PrimaryExaminer-Tim R. Miles Assistant ExaminerSteven A. Markowitz Attorney,Agent, or Firm-Frank H. Thomson [57] ABSTRACT A gas scrubber forremoving particles carried in suspension by gas is used with or withouta specific entrainment separator. The scrubber has (1) a gasconductingconduit with a portion having an inner surface that diverges in thedirection of gas flow, (2) a diverter that is disposed in this portionof the conduit and that has an opposed diverging surface with a greaterdegree of divergence, and (3) a pipe that feeds scrubbing liquid to thatsurface of the diverter for flowing liquid-into the downward flow ofgas. Preferably, the diverter is supported from above and is resilientlyurged upwardly so that the diverter is automatically moved by a changein the rate of gas flow. The scrubber provides an annular flow of gasthat is changed to a helical downward flow by the specific entrainmentseparator, disposed below the diverter and having helically extendingelongated plates in a vertical conduit within a chamber. A frustoconicaldiverter is disposed below the bottom open end of that vertical conduitto change the direction of the gas leaving the vertical conduit. Theelongated plates are radially disposed within the vertical conduit andextend in a helical manner about the longitudinal axis of that conduit.Another conduit communicates tangentially with a sidewall opening of thechamber adjacent its top to exhaust the gas from the annulus between thechamber and the vertical conduit. Accumulated liquid is removed from thebottom of the chamber.

6 Claims, 11 Drawing Figures PAIENTl-Illmzsmm SHEET 1 [IF 3 8798.883PAIENTEDmzs m I SHEET 2 [IF 3 To Separafar 109 k? in PAIENTED MAR 26I974 SHEET 3 [1F 3 GAS SCRUBBER, ENTRAINMENT SEPARATOR AND COMBINATIONTHEREOF BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to a scrubber, i.e., and apparatus that can be used toscrub gas with liquid to remove certain materials. Many waste gases inindustry contain solid particles that are entrained by the gas and thatare either valuable materials requiring their recovery or are materialsthat present air pollution problems when such gas is ultimatelyexhausted to the atmosphere. In other cases, waste gas contains amaterial that can be removed by scrubbing with a liquid in which suchmaterial is soluble. In still other cases, it is desirable to removeboth the particulate material entrained in the gas and certain gaseouscomponents that are soluble in scrubbing liquid. Water is the usualscrubbing liquid.

The invention particularly relates to an apparatus that provides anintimate mixture of the scrubbing liquid and the gas to be treated. Theapparatus is such that the gas during its flow through the apparatusseparates the liquid into extremely small liquid particles that contactthe small solid particles entrained in the gas. Thereafter the physicalmixture of gas and entrained particles of scrubbing liquid, containingtrapped solid particles and/or materials dissolved from the gas by theliquid, are passed to an apparatus that separates the liquid particlesfrom the gas.

Scrubbing apparatus is usually built with a specific combination ofdimensions that provide for a particular optimum narrow range of rate ofgas flow. As a result, most of the prior constructions of gas scrubbersrequire specifically designed units that cannot operate efficiently whenthe gas flow is below or exceeds the limited range for which thescrubber is designed.

The apparatus that usually provide for a centrifugal separation ofscrubbing liquid particles and the gas likewise have their effectivenessaffected by a substantial change in the rate of gas flow. Such separatoris constructed to receive in its chamber a horizontal tangential flow ofgas containing entrained particles of scrubbing liquid. The entrainmentseparators are not designed to receive a vertical, generally annular,flow of gas.

2. Description of the Prior Art U.S. Pat. No. 3,116,348 discloses a gasscrubber in which gas to be treated is passed downwardly through aconduit having a zone in which the inner surface of the wall of theconduit is frustoconical and converging in the direction of gas flow. Inthat zone the scrubber of the patent includes a diverter which is a discthat extends transversely of the direction of gas flow and that has itscenter at the longitudinal axis of the conduit. The peripheral surfaceof the disc, of course, is spaced from the downwardly converging innersurface of this zone of the gas-conducting conduit to permit gas to flowbut with a pressure drop from below by a pipe that is concentric withthis gas-conducting conduit. The disc has an opening so that scrubbingfluid can be forced upwardly, through the pipe and the disc, to contacta deflector member that is parallel to the disc but of smaller diameterthan the disc. The spacing between deflector and disc is adjustable. Thepipe and the disc that it supports are adjustably positioned within theduct. The movement upwardly or downwardly is accomplished mechanicallyunder the control of a gas flowor pressure-sensing means that is mountedin the conduit upstream of the disc.

In the scrubber of U.S. Pat. No. 3,1 16,348, the liquid is diverteddownwardly by the deflector and flows downwardly to the top surface ofthe disc and then to the space between the disc and the converging wallsurface of the conduit. As a result, this liquid is broken up into smallparticles by the gas. These small liquid particles contact and removethe solid particles as well as any gas that is soluble in the scrubbingliquid. After this mixture of liquid particles and gas pass downwardlythrough the annulus that is formed between the disc and the downwardlyconverging wall surface, there is substantial pressure drop. The gascontinues its downward flow. The gas with its entrained particles ofscrubbing liquid then is diverted to a horizontal flow by a downstreamcurved portion of the conduit. This end of the conduit communicatestangentially with a sidewall opening of an entrainment separator inwhich this gas is given a centrifugal path of travel by which liquidparticles fall to the bottom of the tank for collection and removalwhile the gas moves to a top opening in the separator.

U. S. Pat. No. 3,350,076 discloses a gas scrubber that is stated to bean improvement over the scrubber disclosed in the patent mentionedabove. In the scrubber of this later patent, the disc of the priorscrubber is present along with the deflector. The tube that supports thedisc feeds scrubbing liquid to the deflector which directs the liquid tothe top surface of the disc. In this later scrubber, the disc and thedownwardly converging inner surface of the conduit is spaced a greaterdistance than in the case of the earlier scrubber. However, the spacethrough which the gas must pass is limited by an expandable toroidaltube that is mounted on the undersurface of the marginal portion of thedisc. The outermost portion of this toroidal tube is beyond theperiphery of the disc to provide an annulus between the outersurface ofthis section of the tube and the downwardly converging innersurface ofthe wall of this portion of the conduit. Pressurized air is supplied tothe toroidal tube by a pipe extending through the wall of the conduitand into the tube. The pressure of the air determines the degree of theexpansion of the tube and thus 1 determines the width of this annulusthrough which the gas being treated must pass. The disc and toroidaltube are maintained at a fixed elevation. Variation in gas flow iscompensated for by the change in the width of this annulus through thechange in the degree of expansion of the toroidal tube.

U.S. Pat. No. 2,621,754 describes a different construction for a gasscrubber but, again, the scrubbing occurs in an end zone of agas-conducting duct that is converging in the direction of gas flow. Athrottle, that is disposed within the conduit, has a bottom part that isdownwardly converging where it opposes this converging end of the gasconduit to create an annulus through which the gas must pass beforethere is a pressure drop. Water is fed tangentially to the gas stream inthe form of a spray of liquid above the thrott e.

U. S. Pat. No. 2,621,754 also describes various prior methods forremoving suspended material from gases, namely, methods that useapparatus known as spray towers, centrifugal scrubbers, bag filters,cyclone separators, and electrostatic precipitators. A gas scrubber forremoval of suspended particles over a wide range of size, includingsubmicron size, is claimed to be more suitable than the other types ofapparatus mentioned above.

SUMMARY OF THE INVENTION This invention relates to a gas scrubber, to anentrainment separator and to a combination of the two. The gas scrubberof the present invention is an apparatus that includes a conduit toconduct a gas to be treated by scrubbing with a liquid while passing ina downward direction. The conduit includes a portion in which the wallof the conduit has an inner surface that diverges in the downwarddirection, i.e., in the direction of gas flow. The apparatus alsoincludes a gasdiverting means supported in that portion of thegasconducting conduit. At least a portion of the upper surface of thegas-diverting means faces or opposes that diverging inner surface ofthat portion of the conduit. That surface portion of the gas-divertingmeans is downwardly diverging at a greater rate of divergence than thatof the diverging, opposing inner surface of the conduit. These opposeddiverging surfaces are generally frustoconical surfaces.

The downwardly diverging surface of the gasdiverting means constitutes amajor portion of the outer part of the upwardly facing surface of thegas diverting means and can extend to the periphery of that upwardlyfacing surface; however, a small outer marginal part of that upwardlyfacing surface can be normal to the vertical axis and in that case thatmarginal surface can be joined to the frustoconical part by a concavelycurved portion of the surface so that the downwardly diverging portionchanges to a horizontal marginal surface through a curved surface sothat the three surfaces along a line correspond generally to a topsurface of a ski jump.

The gas scrubber of the present invention further includes means tosupport the gas-diverting means so that it is located concentric withthe portion of the conduit that has the downwardly diverting innersurface. Also included in the gas scrubber of the present invention ismeans to furnish scrubbing liquid to the upwardly facing, downwardlydiverting surface portion mentioned above as part of the gas-divertingmeans.

As seen later in connection with some of the preferred embodiments ofthis apparatus, the gas-diverting means is preferably supported fromabove by a rod that is connected to the top of the gas-diverting meansand that extends vertically up through the conduit. At the same time therod extends through a liquid-feeding pipe that has a bottom outlet fromwhich the liquid can flow on to the downwardly diverging surface portionof the gas-diverting means.

In another illustrated embodiment described below, the support for thegas-diverting means is a rod that extends downwardly from thegas-diverting means and ultimately passes through the wall of thegasconducting conduit. in this embodiment of the scrubber, a water pipehas an outlet above the top surface of the gas-diverting means and thepipe above that outlet extends through the sidewall of the conduit.

Also seen later with respect to the especially preferred embodiment ofthe scrubber of this invention the support for the gas-diverting means,i.e., the rod that extends upwardly, is supported at its other end in amanner to resiliently urge upwardly the gas-diverting means. Thus thelatter assumes a maximum elevation at minimum gas flow rate. Thiselevation is substantially above its minimum elevation which occursduring maximum gas flow rate. In both positions and in the intermediatepositions for the gas-diverting means, its downwardly diverging surfacealways opposes a part of the downwardly diverging inner surface portionof the conduit.

The other apparatus of the present invention, namely, the entrainmentseparator, is useful for the separation of scrubbing liquid from the gasin which it has become entrained in a gas scrubber and when the generalflow of such gas from the zone of pressure drop in the scrubber is anannular flow. Such annular flow is obtained by utilizing the gasscrubber of this invention and can be obtained by the use of some of thegas scrubbers of the prior art. it is preferred that this entrainmentseparator be utilized in combination with the gas scrubber of thepresent invention. Such combination also constitutes an apparatus ofthis invention.

The entrainment separator of the invention comprises a vessel thatpreferably has its sidewall in cylinder form. This vessel of theentrainment separator has an opening in its top wall for communicationwith a bottom opening or outlet of a gas-conducting conduit that is partof a gas scrubber that provides such annular flow at the outlet. Thisopeningin the top wall of the vessel, that provides the large outerchamber for the separator, is circular, preferably with its center atthe longitudinal axis of the vessel having the preferred cylindricalsidewall. The separator includes a vertical cylindrical conduit or pipethat is disposed concentric with the top opening of the vessel. Thevertical pipe or conduit of the separator provides an inner chamber andhas an inner diameter generally corresponding to the outer periphery ofthe annular flow of gas to be received from the gas scrubber.

The entrainment separator also includes means within the verticalconduit to divert the annular flow of gas into a helical flow of gasabout an axis concentric with the vertical conduit. This divertingmeans, to pro vide a helical flow in this inner chamber, comprisespreferably a number of elongated plates that extend from the innersurface of the vertical conduit in a radial direction toward thelongitudinal axis of that vertical conduit. At the same time the platesextend from the inner surface of the vertical conduit in a radialdirection toward the longitudinal axis of that vertical conduit. At thesame time the plates are twisted helically in their direction ofelongation, i.e., downwardly, and about a common vertical axisconcentric with the longitudinal axis of the vertical conduit to providea helical path for arcuate segments of the annular flow. These elongatedhelically-directed plates have their inwardly facing elongated edgespaced from that common axis. In the preferred embodiment these inneredges of the plates abut a vertical pipe that is within and is coaxialwith the vertical conduit that surrounds these plates. This constructioninsures the maximum degree of imparting of the helical flow of the gasfrom the scrubber to the bottom of the vertical conduit of theentrainment separator.

in the preferred embodiment for the construction of the elongated platesof the entrainment separator, the bottom portion of these plates in thevertical conduit has a reduced pitch with respect to their spiraldirection in comparison with that for the top part of these plates. Thiscan be a gradual reduction in the pitch from the top to the bottom ofthese plates. This pitch reduction from top to bottom provides anacceleration of the degree of helical flow of the gas through thevertical conduit in which these plates are located.

The entrainment separator has a bottom outlet for withdrawing separatedscrubbing liquid with its entrained solid particles and/or dissolvedgas. The separator also includes a deflector plate supported above thebottom wall of the vessel and above the liquid level to be maintained inthe entrainment separator. This deflector has a larger dimension thanthe vertical conduit in which the helical path of flow is imparted tothe gas and its upper surface is annularly disposed with respect to thelongitudinal axis of that vertical conduit. Preferably this deflectorplate has a conical upper surface with its apex located in thelongitudinal axis of the vertical conduit of the separator. Thisdeflector plate or means receives liquid separated from the gas duringits passage through the vertical conduit and allows the liquid to flowdownwardly and outwardly to the periphery of that plate from which itfalls to the level of liquid to be maintained in the bottom of thevessel of the entrainment separator. At the same time this deflectormeans prevents the gas from the vertical conduit from contacting thepool of liquid at the bottom of the vessel. This prevents a mixing ofthe gas with the pool of liquid. Furthermore, this plate also assists inthe change in direction of the gas that has left the vertical conduit,so as to force the gas to flow upwardly around the vertical conduitwithin the annulus or space between that conduit and the vessel of theentrainment separator. This rapid change in direction, which can beeffectuated in part by additional diverters or change in shape of thebottom ends of the elongated plates below the vertical conduit, resultsin a further separation of water particles from the gas. The gas in itsupward flow continues to have a helical pattern of flow that providesfurther separation, if necessary, of liquid from the gas.

To maintain this desirable flow in that annulus within the vessel, theentrainment separator includes an outlet conduit for the vessel that isin communication with an opening in the sidewall of the vessel adjacentthe top wall. The horizontal longitudinal axis of the outlet conduit istangential to a concentric circle within the cylindrical vessel and theoutlet extends from that sidewall in a direction corresponding to onecomponent of direction of gas flow at that opening in the sidewall. Thisavoids an exit of gas in a horizontal direction requiring a reversal ofdirection of flow of gas that would adversely affect the helical flowupwardly in the annulus between the vessel and the vertical conduit.

The bottom end portion of the vertical conduit is provided preferablywith a number of notches that are generally triangular in shape andcorresponding to the number of elongated plates within that conduit.Thus each notch has a vertical edge and a downwardly inclined edge fromthe top of the vertical edge in the direction of the helical path of theelongated plates. The inclined edge is somewhat curved concavely asviewed from below. The lowermost part of the conduit abuts preferablythe deflector cone. Also preferably vertical baffles extend outwardly,preferably tangentially, from these vertical edges of the conduit thatdefine part of the notches. These baffles abut the deflector plate andcan extend beyond it to or almost to the wall of the vessel.

This construction insures the desirable rapid change in direction of gasflow from downward to upward and does not disrupt the direction ofhelical flow, i.e., clockwise or counterclockwise, as viewed from above,that is determined by the helical twisting of the elongated plates.

DESCRIPTION OF THE DRAWINGS The drawings show preferred embodiment ofthe scrubber of the present invention or of the entrainment separator ofthe invention or of various combinations of these embodiments of the gasscrubber and the entrainment separator. In these drawings similar partsare generally identified by the same numerals.

FIG. 1 is a vertical sectional view of a combination of one embodimentof the gas scrubber of the invention combined with one embodiment of theentrainment separator of the present invention.

FIG. 2 is a cross-sectional view of the entrainment separator as shownin FIG. 1 and taken along the line to 22 of FIG. 1.

FIG. 3 is a fragmentary bottom plan view of part of that entrainmentseparator as seen from line 33 of FIG. 1.

FIG. 4 is a fragmentary vertical section, partly schematic and partlybroken away, showing another embodiment of the gas scrubber of theinvention.

FIG. 5 is a fragmentary vertical section, partly schematic, of stillanother embodiment of the scrubber of the present invention.

FIG. 6 is a vertical section, also partly schematic, of still a furtherembodiment of the gas scrubber of the invention.

FIG. 7 is a fragmentary vertical section, partly schematic, of yetanother embodiment of the scrubber of the present invention.

FIG. 8 is a vertical section of another embodiment of the entrainmentseparator of the present invention and a fragmentary sectional view ofthe bottom part of one embodiment of the gas scrubber of the invention.

FIG. 9 is a cross-sectional view of the entrainment separator of FIG. 8taken along the line 9-9 of FIG. 8.

FIG. 10 is a fragmentary vertical sectional view of the entrainmentseparator of FIG. 8 taken along the line 10-l0 of FIG. 9.

FIG. 11 is a fragmentary elevational view of some of the internalcomponents of a modified embodiment of the entrainment separator of thepresent invention.

DETAILED DESCRIPTION FIG. 1 illustrates an apparatus of the presentinvention, namely, a combination of gas scrubber and entrainmentseparator. The apparatus comprises a gas scrubber generally indicated at21 and an entrainment separator indicated at 22. The gas scrubber 21 hasan inlet 23, that receives in this illustration gas in a horizontalflow, and has a bottom outlet 24 that exits the gas in a downwardlyvertical direction into the central inlet opening 25 of a top wall 26 ofa vessel generally indicated at 27 of entrainment separator 22. The gasthen exits from vessel 27 by a conduit 28 that communicates with anopening 29 (see FIG. 2) in a sidewall 30 of vessel 27.

.lar. The conduit 32 has a bottom portion that has a wall with an innercylindrical surface in portion 33 below which is a downwardly diverging,somewhat frustoconical surface 34 that is intermediate surface 33 and acylindrical surface 35 that extends to outlet 24 of gasconductingconduit 32.

The wall of the bottom part of conduit 32 is flanged at both ends andthe bottom flanged end is mounted on wall 26 so that cylindrical surface35 is an extension of top wall 26 at opening 25 so that outlet 24communicates to the full extent with vessel 27 at opening 25. At thesame time the top flanged end of this lower portion of conduit 32 isbolted to the flanged bottom end of curved pipe 31. Between theseflanges, that are bolted together to join the two portions of conduit32, is mounted a peripheral ring 36 that is joined to a sleeve 37 byspider spokes 38 so that sleeve 37 is centrally positioned at the inletof the bottom part of conduit 32 adjacent the outlet of curved portion31 without impeding gas flow through conduit 32.

The sleeve 37 provides a part of the positioning for a water-supply tube39 that is vertically disposed in the vertical part of curved portion 31and extends through sleeve 37 into the bottom part of conduit 32. Tube39 extends upwardly through an opening 40 in a curved portion 31. Atthis opening it is joined to gasconducting conduit 32. The upperextension of tube 39 is above an opening 40 and has a bearing 41 inwhich is received rod 42 that supports a gas-diverting means generallyindicated at 43 in the bottom part of conduit 32.

Adjacent to the top end of tube 39 is an opening 44 for connection oftube 39 with a pipe 45 that is connected to a water supply (not shown).Thus water from the supply is fed to tube 39 and passes out its bottomend at which is located a spider bearing 46 that maintains with bearing41 a coaxial positioning of rod 42 with respect to tube 39 that isfixedly supported as described above. The bearings 41 and 46 permitaxial movement of rod 42.

The gas-diverting means 43 is mounted on the bottom end of rod 42. Thegas-diverting means 43 has an upwardly facing surface 47 that isdownwardly diverging to its maximum width below which gas-divertingmeans 43 has an inverted conical surface 48. The degree of divergence ofsurface 47 is greater than the degree of divergence of surface 34 of thegas-conducting conduit 32, that it faces at its various elevations atwhich it is supported by rod 42.

The gas-diverting means 43 and its support rod 42 are upwardly urged bya piston 50 that is part of an air cylinder generally indicated at 51that further includes a cylinder 52 having a bottom end inlet 53 and anoutlet 54 adjacent the top end of cylinder 52. The inlet 53 communicateswith a pipe 55 that is connected to a pipe 56 by a pressure regulator 57that is also a pressure relief valve. The pipe 56 is in communicationwith a pressurized air source (not shown). The outlet 54 of cylinder 52is connected to a pipe 58 that is open in the use of air cylinder 51.The piston 50 is raised to a desired height by pressurized air in thebottom chamber of cylinder 51. The pressure of air admitted to cylinder51 below piston 50 is controlled by regulator 57.

The pressure of air in the lower chamber of cylinder 52, i.e., thechamber below piston 50, is chosen so that gas-diverting means 43 iselevated to a position corresponding to the minimum gas flow expectedfor the use of gas scrubber 21. For illustration, it is assumed thatthis position is that shown in dotted lines in FIG. 1. As the gas flowis normally greater than the expected minimum, the gas flow shown by thearrow at the upper lefthand part of curved portion 31 passes downwardlyinto the bottom portion of conduit 32 where it is impeded by theconstriction effectuated by the presence of gasdiverting means 43 withinthe bottom portion of conduit 32. As a result, the pressure of thisflowing gas forces downwardly gas-diverting means 43 that is resilientlyurged upwardly by air cylinder 51.

In FIG. 1 the lowermost position of gas-diverting means 43 isillustrated by solid lines that show the outline or shape of thegas-diverting means. In this illustration it is assumed that gas isflowing into gas scrubber 21 at a rate and a gas pressure sufficient tomove gasdiverting means 43 downwardly from the position shown in dottedlines to this lowermost position. As the gas flow rate is decreased, inview of existing variations in flow, the downward force on gas-divertingmeans 43 will decrease. As a result air cylinder 51 will raisegasdiverting means 43 until the annulus between it and diverging surface34 is decreased to the extent that the back pressure prevents anyfurther upward movement of gas-diverting means 43 by air cylinder 51.

During the operation of gas scrubber 21, the forces acting ongas-diverting means 43, which can also be referred to as an orificepressure drop regulator, are the weight of that regulator and rod 42 andthe reaction forces of the scrubbing liquid and the gas stream. Theseforces are opposed by a constant force that is supplied by a pneumaticcylinder, illustrated by air cylinder 51, or by any other similar devicesuch as an adjustable spring-force mechanism. The weight of the pressuredrop regulator assembly and the reaction force of the scrubber liquidwill remain essentially constant for any given unit. The reaction forceof the gas stream is proportional to the pressure drop across thepressure drop regulator. Since the opposing force is maintained at aconstant value by means of a pressure regulator and relief valve, theorifice pressure regulator will automatically adjust its position in thedivergent duct section, i.e., the section of gas-conducting conduit 32that has downwardly diverging inner wall 34, so as to maintain thepressure drop required to maintain a force equilibrium for a wide rangeof system volumes.

Any desire pressure drop, which is proportional to the efficiency of thescrubbing action, can be attained and then maintained by adjusting theexternal force for the system, i.e., by adjusting the upwardly urgingforce provided by the air cylinder.

The inverted conical surface 48 of the bottom part of gas-divertingmeans 42 acts as a diffuser to provide some static regain from the highvelocity gas stream. This is one other advantage of the gas scrubber ofthis embodiment of the present invention.

The entrainment separator 22 receives the generally annular gas flowfrom gas scrubber 21 when the gas flow exits from bottom opening 24 ofscrubber 21 and enters top opening 25 of vessel 27. This gas flow isprevented from diverging into the entire width of vessel 27, as itpasses through opening 25, by the presence of a vertical conduit 60 thathas a top flange 61. The outwardly directed flange 61 abuts the bottomsurface of top wall 26 of vessel 27 and is fixed in position by bolts 62that also extend through a flange 63 at the bottom end of conduit 32.The flange 63 is mounted on top wall 26.

A number of elongated plates 64 are fixedly mounted in a verticalconduit 60. The plates 64 are twisted in a helical path about thelongitudinal axis of vertical conduit 60. The plates 64 have their outerelongated edges abutting vertical conduit 60. The plates 64 have theirwidth extending inwardly along radii of vertical conduit 60, but in thispreferred embodiment plates 64 have a width less than the radius ofcylindrical vertical conduit 60. Thus a central cylindrical passageextends from the top of conduit 60 to its bottom end. The elongatedplates 64 divide the outer annular portion of any cross section ofconduit 60 into a number of segments that extend downwardly from opening25 to the bottom open end of conduit 60 but these segments provide ahelical path because of the nature of the twisting of plates 64. Thishelical path converts the received generally annular downward flow ofgas and converts it to a downward helical flow about the longitudinalaxis of conduit 60.

As seen in FIG. 1, the bottom ends of elongated plates 64 haveextensions 65 that are below conduit 60. These extensions 65 are nottwisted, as are the main portions of plates 64, but they are tilted withrespect to the longitudinal axis of conduit 60. Furthermore, extensions65 have flanges 66 that are upwardly directed and at right angles to themain part of extensions 65.

The helical path of the gas passing downwardly through conduit 60 asprovided by plates 64 results in a separation of entrained liquidparticles from the gas and these particles fall onto the upper surfaceof plates 64 and the inner surface of conduit 60. The liquid depositedon plates 64 flow downwardly along the top surface of extensions 65 ontoa conical diverter 67 that is supported by legs 68 that are mounted onan inverted concial bottom wall 69 of vessel 27. The wall 69 has acentral outlet 70 for withdrawal of fluid separated from the gas. Thelegs 68 support conical diverter 67 above the level of liquid in thebottom part of tank 27. The separated liquid is withdrawn through outlet70 at a sufficient rate to maintain this spacing.

The flanges 66 prevent the gas from sweeping across the surface ofextensions 65 over which separated water or other scrubbing liquid isflowing; otherwise, the gas would pick up some water and this would beundesirable.

As liquid falls onto the conical diverter 67, it flows down its topsurface which is inclined, of course, and flows off the periphery ofdiverter 67 and down to the body of separated liquid that is below.

The helically travelling gas from which the liquid has been separatedtravels radially and upward with respect to the longitudinal axis ofvessel 27 to continue a helical path. That travel is in the annulusbetween conduit 60 and sidewall 30. The helical flow upwardly throughthe annulus is generally the same as that direction for the flowdownwardly within conduit 60 as these flows would be viewed from above.

Referring to FIG. 4, the gas scrubber of this embodiment has a toparcuate portion 31 for gas-conducting conduit 32 and an inlet opening23. The bottom portion of conduit 32 has cylindrical surface 33,frustoconical surface 34 and cylindrical surface 35 in that order in thedownward direction. The sleeve 37 serves as a bearing for water tube 39,The sleeve 37 is supported by spokes 38 supported by conduit 32. At theplace where tube 39 extends through opening 40 in conduit 32, there is abearing 80. Tube 39 is adjustably supported by a rod 81 that is moved ina vertical direction by suitable means (not shown) to position thegasdiverting means 43 mounted on the bottom end of tube 39. The tube 39near its top end has a side tube 82 that is connected to a flexible tube83 that is connected to a water supply (not shown). The tube 83 isflexible to permit its connection with tube 82 even though the latter ismoved vertically.

The gas-diverting means 43 has a top upper surface 47 that is downwardlydiverting to a greater degree than the divergence of surface 34 ofconduit 32. This difference in the degree of divergence, that is thedifference between the included angles of the divergences, is preferablysuch in this embodiment and in appropriate other embodiments that thevertical movement decreases the spacing between gas-diverting means 43and diverting surface 34 upon upward movement of the former. This occursupon a decrease in gas flow. This change in spacing does not change thevelocity of gas flow between diverging surface 34 and the peripheralpart of the upper surface 47 of gas diverting means 43. Thus, thepressure drop remains about the same and the efficiency of the scrubberremains somewhat constant.

The scrubbing liquid, that is fed to tube 39, flows out holes 85 at thebottom portion of tube 39 onto surface 47.

The gas scrubber 21 in FIG. 4 can be mounted on and in communicationwith an entrainment separator of the invention such as the type shown inFIG. 1 or can communicate by a bottom bend in conduit 32 to provide ahorizontal path of travel to a conventional entrainment separator thathas been described above. Of course, the latter combination is also thecase with respect to scrubber 21, that is shown in FIG. 1 in combinationentrainment separator 27 of the present invention.

Referring to FIG. 5, the gas conducting conduit 32 has generally thesame construction as that shown in FIG. 4 except for one modification,namely, the modifl cation that appears at the juncture of the bottomportion of conduit 32 between cylindrical inner surface 33 andfrustoconical inner surface 34. At that zone, the apparatus is providedwith an annular pipe that is fed water by a pipe 91 from a water supply(not shown). In addition, annular pipe 90 has inwardly directed openingscommunicating with complementary openings in conduit 32 to provide waterinlets 92 for the introduction of water into the path of travel of thegas flow and to flow downwardly along surface 34. Because surface 34 isdownwardly diverging, the erosion by the gas to be treated is greatlyminimized whereas the erosion of the downwardly converging surfaceutilized in apparatus of the prior art is a substantial problem that isnot adequately solved by flowing water along that surface. The erosionis attributed, at least in part, to solid particles that are beingcarried into scrubber 21 or scrubbers of the prior art. In thosegasconducting conduits of the prior art, the inclined wall is facing theoncoming gas stream whereas the gas scrubber of the present inventionthis surface is facing in the opposite direction.

The scrubber 21 shown in FIG. 5 differs from that shown in FIG. 4 inseveral other respects. The gasdiverting means 43 has the general shapeof those shown in FIGS. 1 and 4, except as stated below. Thegas-diverting means 43 of FIG. 5 has, in its upper surface 47, anannular recess 93 that is coaxial with water pipe 39. The bottom openend of pipe 39 extends in re cess 93. The gas-diverting means 43includes a central upstanding rod 94 that extends upwardly and coaxiallywith recess 93. The rod 94 extends through the entire length of watertube 39 and above and is a support that is mounted on a fixed support(not shown). The rod 94 can be adjustably raised or lowered or can beautomatically lowered as in the case of rod 42 of scrubber 21 in FIG. 1by an air cylinder or other equivalent means.

The rod 94 maintains tube 39 in its coaxial position by bearing 41 atthe top end of tube 39 and by bearing 46 intermediate the two ends oftube 39 so that gasdiverting means 43 can be raised or lowered relativeto surface 34 and relative to pipe 39. The pipe 39 is fixedly mounted atits entrance into conduit 32.

As seen in FIG. 5, surface 47 outwardly of recess 93 is downwardlydiverging at a uniform rate for a substantial distance and thendiverting at a decreasing rate to or almost to the juncture betweensurface 47 and surface 48 of the lower portion of gas-diverting means43. As a result, the outermost part 96 of surface 47 is arcuate in anyline. The result is a surface 47 that along a radial line has the shapegenerally of the longitudinal top surface of a ski jump.

Water is fed to tube 39 by side tube 45 that receives water from thesupply (not shown). This water flows downwardly to the bottom part oftube 39 where it flows between tube 39 and central rod 94 into thelowermost part of recess 93. Then it flows upwardly in the annulusbetween tube 39 and recess 93. It overflows from recess 93 along the skijump surface 47 to the periphery of that surface. In this travel onsurface 47 and thereafter in the constricted space between gasdivertingmeans 43 and diverging inner surface 35, the water is converted by thegas flow to liquid particles in the scrubbing action on the gas.

Referring to FIG. 6, gas-conducting conduit 21 has an upper part 101that is cylindrical instead of the arcuate portion 31 of theearlier-described upper section 31 of FIGS. 1 through 5. This merelyindicates that the gas being received in the lower portion ofgas-conducting conduit 21, need not be arcuate. The rear difference inthis embodiment is underneath support of gas-diverting means 43 by a rod102. The gas-diverting means 43 is centrally supported at its bottomsurface. The rod 102 is supported at its bottom ends by means (notshown).

Movement of rod 102 in a direction other than its longitudinal axis isprecluded by a bearing 103 supported by spider spokes 104 mounted on andsupported at their outer ends by gas-conducting conduit 32,illustratively, in the region wherein cylindrical inner surface 35 ispresent. Similarly, lateral movement of rod 102 is prevented by abearing 105 mounted on conduit 32 at an opening 106 in a still lower andarcuate portion 107 of gas-conducting conduit 32.

The gas-diverting means 43 of the embodiment illustrated by FIG. 6 has abottom flat surface 108. The rest of the surface of gas-diverting means43 is upwardly facing in the form of 2 frustoconical surfaces ofdifferent included angles 109 and 110. The upper surface 110 has thegreater included angle. The lowermost frustoconical surface 109, likesurface 47 of earlierdescribed gas-diverting means 43, also facesfrustoconical surface 34 of gas-conducting conduit 32. As the gas flowsdownwardly between surfaces 34 and 110, there is an acceleration of gasflow because of the increasing constriction in the downward directionbetween these surfaces. At the bottom'edge of surface the gas reachesits maximum velocity. The upper frustoconical surface 110 receives aflow of water from a pipe 111 that extends horizontally throughgas-conducting conduit 32 at or above the zone where cylindrical surface33 is located. The pipe 111 is downwardly curved.

within conduit 32 and its bottom portion of conduit 32 is coaxially withgas-diverting means 43. The water flows outwardly along surface 110 andthen along surface 109.

In this embodiment, the difference in the degree of divergence betweensurfaces 34 and 109 is such, that for any position of gas-divertingmeans 43, the area of the annular space will remain constant and thevelocity of the gas as it passes between these surfaces will remain thesame as it was when it passed the space between surface 34 and thebottom edge of surface 110. Of course, this area will change upon movingmeans 43 up or down. The scrubber of this embodiment does not providefor the automatic adjustment or positioning of gas-diverting means 43that can occur with other embodiments such as that shown in FIG. 1.

Referring to FIG. 7, scrubber 21 has water pipe 39 mounted generally asshown in FIG. 5 with its water supplied by side pipe 45 from a watersource (not shown). Again, a rod 42 supports gas-diverting means 43 ingas-conducting conduit 32 which has curved upper portion 31 and thelower portion with its cylindrical surface 33, frustoconical surface 34and cylindrical surface 35 in that order going downstream. The rod 42 issupported for vertical movement by means (not shown) and is unitary atits bottom end with means 43. The rod 42 is maintained coaxially withpipe 39 by bearing 41 and 46. As in the earlier construction, bearing 41also serves as a seal to prevent upward escape of water fed into pipe39.

In this embodiment, the top part of upperly facing surface 47 isoutwardly curved from rod 42 to an outer portion that is frustoconicaland that has an includedangle that is larger than that of inner surface34 of conduit 32. With this configuration also, it is possible toprovide a uniform pressure drop between the bottom of surface 47 andsurface 34 at that transverse plane and to provide a desirable directionof flow throughout the height of frustoconical surface 47 regardless ofthe vertical movement of means 43 within the zone of conduit 32 wheremeans 43 faces surface 34.

In the embodiment shown in FIG. 7, the bottom part of conduit 32 isextended in an arcuate manner as in the case of that of FIG. 6, butinstead it could be mounted on entrainment separator 37 for the use ofthe latter as described earlier in connection with FIG. 1.

Referring to FIG. 8, scrubber 21 possesses basically the construction ofscrubber 21 in FIG. 1 except for the absence of cylindrical surface 35.That surface is provided in effect by an upper extension of verticalconduit 60. In this embodiment, vessel 27 of entrainment separator 22has a top wall 26 that is upperly inclined to central opening 25 abovewhich wall 26 extends by a flange 112 that surrounds the upper extensionof conduit 60 mentioned above. At the top of flange 112, wall 26 isextended outwardly by a flange 113. A flange 114 similarly extendsoutwardly from the bottom end of conduit 32. The flanges 113 and 114 arebolted to each other.

The entrainment separator 22 has elongated plates 64 mounted in conduit60 as in FIG. 1. The plates 64 at their bottom abut conical diverter 67that has a central flat portion parallel to a transverse plane. Theseparator 22 is provided with baffles 115. Each baffle 115 extendstangentially from the vertical edge of a generally triangular bottomnotch 118 in conduit 60. These notches are seen in FIG. 10. The upperedge of each notch 118 is curved downwardly in the direction ofcurvature of plate 64 and that edge is concave as viewed from below. Themajor surfaces of baffles 115 are in vertical planes. The baffles 115prevent gases that emanate from conduit 60 from moving across the uppersurface of diverter 67 where liquid could be thereby reentrained in thegas.

The diverter 67 is supported by legs 68 mounted on inclined bottom 69that has a central opening 70 for removal of water to vessel 27 tomaintain a pool of water below a predetermined level as in theembodiment of FIG, 1.

In FIG. 8, the gas-diverting means 43, for purpose of illustration, hasthe construction shown in FIG. 1. The entrainment separator 22 isprovided with a gas-exit conduit 28 that is tangentially communicatingwith vessel 27 in the same manner as described above for the apparatusof FIG. 1. The tangential direction of baffles 115 are more clearly seenin FIG. 9.

Referring to FIG. 11, the plates 64 have a decreased pitch at theirbottom ends to provide a greater degree of helical flow per unit lengthin the downward direction. This provides a greater centrifugal force forseparation of water from the gas.

The flow of gas to be treated, the flow of water used as scrubbingliquid and the flow of separated water and of separated, treated gas areshown in some of the drawings by appropriate arrows.

The foregoing description of various embodiments of the apparatus of theinvention, either scrubber or entrainment separator or a combination ofthese, have been presented for the purpose of illustration only. Variousmodifications will be apparent to one of ordinary skill in this art fromthe foregoing description and from the drawings.

For example, instead of using plates 64 in entrainment separator 22,there can be other means for converting an annular flow to a helicalflow. Such other construction could be individual longitudinally spaceddiverter plates within conduit 60. Accordingly, the present invention islimited only by claims that follows.

I claim:

1. An apparatus for use in the removal of material from a gas byscrubbing with a liquid and separating the resultant liquid particlesfrom the gas in which the liquid becomes entrained; said apparatusincluding an entrainment separator which comprises:

a cylindrical vessel with a top wall having an opening to provide aninlet for downwardly directed gas from a scrubber and containingentrained scrubbing liquid, with a side wall having an opening near thetop wall and with a bottom wall having an openmg;

a vertical cylindrical conduit extending downwardly in, and coaxiallyaligned with, said vessel from said opening in the top wall, to receiveall gas passing downwardly through said opening, and spaced from thebottom wall;

means within said vertical conduit to convert a generally annular flowof gas received in the top end of said vertical conduit to a helicaldownward flow about the longitudinal axis of said vertical conduitcomprising elongated flat plates extending downwardly and outwardly,twisted in a helical manner about the longitudinal axis of the verticalconduit and extending inwardly from the inner surface of the verticalconduit to provide the major surfaces of each plate generally at radiiof the circle at the various elevations of the vertical conduit, and atleast one of the said extensions having a vertical downwardly inclinedflange at one end constituting the outer tangential end of theextension, said plates extending below the vertical conduit;

means between the vertical conduit and the bottom wall of the vessel todivert the helical downward gas flow to an outward flow and subsequentupward flow, said means having at least the upper surface of the outerportion of said means below the vertical conduit as a conical surface;

a gas-exit conduit extending generally tangentially from the opening inthe side wall in a direction of a component of movement of the helicalupward flow.

2. For use in combination with a gas scrubber, an entrainment separatorfor separating liquid particles from the gas discharged from the gasscrubber comprising:

a vessel having a top wall with an opening therein to define an inletfor receiving gas discharged from said scrubber, a side wall having anopening therein to define an outlet for gas and a bottom wall having anopening therein;

a vertical conduit mounted in said vessel and flow connected to theinlet of the vessel for receiving all of the gas discharged from saidscrubber and spaced from said bottom wall;

means mounted in said vertical conduit for converting the generallyannular flow of gas received from the scrubber to a helical downward gasflow about the longitudinal axis of the vertical conduit;

means for diverting substantially all of the helical downward gas flowto an outward and subsequent helical upward flow toward said outletwhile simultaneously preventing reentrainment of liquid into the gas;

said last-named means having a conical diverter mounted in said vesselbelow said vertical conduit and vertical baffles tangential to thevertical conduit and attached to said conical diverter in the path ofsaid downward gas flow.

3. The apparatus of claim 2 wherein one end of said vertical conduit isclosed by said conical surface and said vertical conduit is providedwith at least one opening therein near said conical surface fordischarging gas from said vertical conduit into said vessel.

4. For use in combination with a gas scrubber, an entrainment separatorfor separating liquid particles from the gas discharged from the gasscrubber comprising:

a vessel having a top wall with an opening therein to define an inletfor receiving gas discharged from said scrubber, a side wall having anopening therein to define an outlet for gas and a bottom wall having anopening therein;

a vertical conduit mounted in said vessel and flow connected to theinlet of the vessel for receiving all of the gas discharged from saidscrubber and spaced from said bottom wall;

means mounted in said vertical conduit for converting the generallyannular flow of gas received from the scrubber to a helical downward gasflow about the longitudinal axis of the vertical conduit;

means for diverting substantially all of the helical downward gas flowto an outward and subsequent helical upward flow toward said outletwhile simultaneously preventing reentrainment of liquid into the gas;

said last-named means having a conical diverter mounted in said vesselbelow said vertical conduit and at least one substantially flat platetwisted in a helical manner about the longitudinal axis of said verticalconduit and extending below the bottom of said vertical conduit.

5. An apparatus for use in the removal of material from a gas byscrubbing with a liquid and separating the resultant liquid particlesfrom the gas in which the liquid becomes entrained, said apparatusincluding an entrainment separator which comprises:

ally annular flow of gas received in the top end of said verticalconduit to a helical downward flow about the longitudinal axis of saidvertical conduit, comprising elongated plates extending downwardly andtwisted in a helical manner about the longitudinal axis of the verticalconduit and extending inwardly from the inner surface of the verticalconduit to provide the major surfaces of each plate generally at radiiof the circle at the various elevations of the vertical conduit, saidconduit extending to said gas diverter between the conduit and thebottom wall of the vessel, said bottom end of said vertical conduithaving generally triangular notches, with one side of each notch beingvertical and another being curved downward in a concave manner from thetop of vertical side to the bottom end of the conduit, and with theadjacent elongated plate having its outer edge at the conduit adjacentthe curved edge of the notch;

means between the vertical conduit and the bottom wall of the vessel todivert the helical downward gas flow to an outward flow and subsequentupward flow, said means having an upper surface that is angularlydisposed and downwardly diverging; and

a gas-exit conduit extending generally tangentially from the opening inthe side wall in a direction of a component of movement of the helicalupward flow.

6. The apparatus of claim 5 wherein the entrainment separator furtherincludes vertical baffles that are mounted on the conical surface of thegas diverter below the vertical conduit and that extend tangentiallyfrom the vertical edges of the notches to reduce liquid pickup by gas,that flows helically down the vertical conduit, after it passes out ofanother notch.

1. An apparatus for use in the removal of material from a gas byscrubbing with a liquid and separating the resultant liquid particlesfrom the gas in which the liquid becomes entrained; said apparatusincluding an entrainment separator which comprises: a cylindrical vesselwith a top wall having an opening to provide an inlet for downwardlydirected gas from a scrubber and containing entrained scrubbing liquid,with a side wall having an opening near the top wall and with a bottomwall having an opening; a vertical cylindrical conduit extendingdownwardly in, and coaxially aligned with, said vessel from said openingin the top wall, to receive all gas passing downwardly through saidopening, and spaced from the bottom wall; means within said verticalconduit to convert a generally annular flow of gas received in the topend of said vertical conduit to a helical downward flow about thelongitudinal axis of said vertical conduit comprising elongated flatplates extending downwardly and outwardly, twisted in a helical mannerabout the longitudinal axis of the vertical conduit and extendinginwardly from the inner surface of the vertical conduit to provide themajor surfaces of each plate generally at radii of the circle at thevarious elevations of the vertical conduit, and at least one of the saidextensions having a vertical downwardly inclined flange at one endconstituting the outer tangential end of the extension, said platesextending below the vertical conduit; means between the vertical conduitand the bottom wall of the vessel to divert the helical downward gasflow to an outward flow and subsequent upwaRd flow, said means having atleast the upper surface of the outer portion of said means below thevertical conduit as a conical surface; a gas-exit conduit extendinggenerally tangentially from the opening in the side wall in a directionof a component of movement of the helical upward flow.
 2. For use incombination with a gas scrubber, an entrainment separator for separatingliquid particles from the gas discharged from the gas scrubbercomprising: a vessel having a top wall with an opening therein to definean inlet for receiving gas discharged from said scrubber, a side wallhaving an opening therein to define an outlet for gas and a bottom wallhaving an opening therein; a vertical conduit mounted in said vessel andflow connected to the inlet of the vessel for receiving all of the gasdischarged from said scrubber and spaced from said bottom wall; meansmounted in said vertical conduit for converting the generally annularflow of gas received from the scrubber to a helical downward gas flowabout the longitudinal axis of the vertical conduit; means for divertingsubstantially all of the helical downward gas flow to an outward andsubsequent helical upward flow toward said outlet while simultaneouslypreventing reentrainment of liquid into the gas; said last-named meanshaving a conical diverter mounted in said vessel below said verticalconduit and vertical baffles tangential to the vertical conduit andattached to said conical diverter in the path of said downward gas flow.3. The apparatus of claim 2 wherein one end of said vertical conduit isclosed by said conical surface and said vertical conduit is providedwith at least one opening therein near said conical surface fordischarging gas from said vertical conduit into said vessel.
 4. For usein combination with a gas scrubber, an entrainment separator forseparating liquid particles from the gas discharged from the gasscrubber comprising: a vessel having a top wall with an opening thereinto define an inlet for receiving gas discharged from said scrubber, aside wall having an opening therein to define an outlet for gas and abottom wall having an opening therein; a vertical conduit mounted insaid vessel and flow connected to the inlet of the vessel for receivingall of the gas discharged from said scrubber and spaced from said bottomwall; means mounted in said vertical conduit for converting thegenerally annular flow of gas received from the scrubber to a helicaldownward gas flow about the longitudinal axis of the vertical conduit;means for diverting substantially all of the helical downward gas flowto an outward and subsequent helical upward flow toward said outletwhile simultaneously preventing reentrainment of liquid into the gas;said last-named means having a conical diverter mounted in said vesselbelow said vertical conduit and at least one substantially flat platetwisted in a helical manner about the longitudinal axis of said verticalconduit and extending below the bottom of said vertical conduit.
 5. Anapparatus for use in the removal of material from a gas by scrubbingwith a liquid and separating the resultant liquid particles from the gasin which the liquid becomes entrained, said apparatus including anentrainment separator which comprises: a cylindrical vessel with a topwall having an opening to provide an inlet for downwardly directed gasfrom a scrubber and containing entrained scrubbing liquid, with a sidewall having an opening near the top wall and with a bottom wall havingan opening; a vertical cylindrical conduit extending downwardly in, andcoaxially aligned with said vessel from said opening in the top wall, toreceive all gas passing downwardly through said opening, and spaced fromthe bottom wall; means within said vertical conduit to convert agenerally annular flow of gas received in the top end of said verticalconduit to a helical downward flow about the longitudinal axis of saidvertical conduit, comprising elongated plates extending downwardly andtwisted in a helical manner about the longitudinal axis of the verticalconduit and extending inwardly from the inner surface of the verticalconduit to provide the major surfaces of each plate generally at radiiof the circle at the various elevations of the vertical conduit, saidconduit extending to said gas diverter between the conduit and thebottom wall of the vessel, said bottom end of said vertical conduithaving generally triangular notches, with one side of each notch beingvertical and another being curved downward in a concave manner from thetop of vertical side to the bottom end of the conduit, and with theadjacent elongated plate having its outer edge at the conduit adjacentthe curved edge of the notch; means between the vertical conduit and thebottom wall of the vessel to divert the helical downward gas flow to anoutward flow and subsequent upward flow, said means having an uppersurface that is angularly disposed and downwardly diverging; and agas-exit conduit extending generally tangentially from the opening inthe side wall in a direction of a component of movement of the helicalupward flow.
 6. The apparatus of claim 5 wherein the entrainmentseparator further includes vertical baffles that are mounted on theconical surface of the gas diverter below the vertical conduit and thatextend tangentially from the vertical edges of the notches to reduceliquid pickup by gas, that flows helically down the vertical conduit,after it passes out of another notch.